1. Field of the Invention
The invention relates to an eyeglass lens processing apparatus for processing eyeglass lenses; to a grinding water tank unit for storing and circulating grinding water; and to a processing debris separator for separating grinding water from processing debris.
2. Description of the Related Art
Grinding water is fed to an eyeglass lens processing apparatus in order to cool a portion of a lens to be processed and remove debris produced during the course of processing the lens. A water-supply method employed in this connection may be classified into a waterline direct coupling method for supplying water from a waterline directly to a processing apparatus main unit; and a circulation method. According to the circulation method, grinding water stored in a tank is pumped up and fed to the processing apparatus main unit using a pump. Grinding water having been used is drained into the tank, and the grinding water is then reused.
The waterline direct coupling method presents a problem of processing debris being drained directly into sewage from the processing apparatus main unit together with used grinding water. Even the circulation method suffers a problem of difficulty in completely separating processing debris from grinding water, thereby requiring effort in removing solely processing debris. Another problem of the circulation method lies in that a portion of processing debris is drained into a sewage along with the grinding water stored in the tank at the time of replacement of grinding water.
When a plastic lens is processed, bubbles develop in drained grinding water. Particularly, when the eyeglass processing apparatus of circulation type performs processing operation over a period of time, the tank is filled with bubbles, sometimes resulting in leakage of bubbles from the tank or overflow of bubbles to a processing chamber of the processing apparatus main unit. For this reason, replacement of grinding water and cleaning of inside of the tank must be performed at frequent intervals.